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spindle-mosfet-control [2020/10/22 04:18]
mrscott [Spindle control with a Mosfet] Reference Wikipedia Flyback_diode.
spindle-mosfet-control [2021/02/22 16:58] (current)
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 If you are not using a VFD, and your spindle motor is a DC motor of low enough power (voltage and current, **including** any current extremes when stalled), you can control it directly using the MOSFETs on the Smoothieboard. If you are not using a VFD, and your spindle motor is a DC motor of low enough power (voltage and current, **including** any current extremes when stalled), you can control it directly using the MOSFETs on the Smoothieboard.
  
-MOSFETs are present on-board, but have limited current capacity ( up to 12A ) and need to be protected by a 'flyback' diode when controlling a motor, electromechanical relay or other inductive load.  See [[https://en.wikipedia.org/wiki/Flyback_diode|Wikipedia Flyback_diode]].+MOSFETs are present on-board, but have limited current capacity ( up to 12A ) and need to be protected by a 'flyback' diode when controlling a motor, electromechanical relay or other inductive load.  See [[https://en.wikipedia.org/wiki/Flyback_diode|Wikipedia Flyback_diode]] and [[https://electronics.stackexchange.com/questions/358210/driving-inductive-load-from-ic-with-mosfet|Driving inductive load, Electronics StackExchange]].
  
 Motors have the property of inductance, which is the electrical equivalent of inertia.  The motor current will continue to flow after the MOSFET is switched off, because the energy stored in the inductor by the current does not instantly disappear.  The current will decrease as the stored energy is dissipated.  This current flow results in the voltage across the motor reversing and increasing (or "spiking") until the current finds a path to flow.   Motors have the property of inductance, which is the electrical equivalent of inertia.  The motor current will continue to flow after the MOSFET is switched off, because the energy stored in the inductor by the current does not instantly disappear.  The current will decrease as the stored energy is dissipated.  This current flow results in the voltage across the motor reversing and increasing (or "spiking") until the current finds a path to flow.  
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 The same considerations apply to other inductive loads such as solenoid valves and relay coils. The same considerations apply to other inductive loads such as solenoid valves and relay coils.
  
-[http://smoothieware.org/general-appendixes#solidstaterelay Solid state relays] are controlled via a GPIO pin, and can control higher loads, but are on/off only ( no control of the exact amount of power sent via PWM ). For more information about SSRs, [[http://smoothieware.org/general-appendixes#solidstaterelay|see this appendix]].  +[[http://smoothieware.org/general-appendixes#solidstaterelay|Solid state relays]] are controlled via a GPIO pin, and can control higher loads, but are on/off only ( no control of the exact amount of power sent via PWM ). For more information about SSRs, [[http://smoothieware.org/general-appendixes#solidstaterelay|see this appendix]].  
  
 <callout type="warning" icon="true" title=" Diodes"> <callout type="warning" icon="true" title=" Diodes">
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 <div class='panel panel-default wrap_right' style='width:450px;padding:10px '> <div class='panel panel-default wrap_right' style='width:450px;padding:10px '>
 <div class='panel-heading'><h4 class='panel-title'>Mosfet power input and outputs</h4></div> <div class='panel-heading'><h4 class='panel-title'>Mosfet power input and outputs</h4></div>
-<image src='http://chibidibidiwah.wdfiles.com/local--files/3d-printer-guide/smoothieboard-mosfets.png' width='430px'><br/>+<image src='/_media///external/http.chibidibidiwah.wdfiles.com.local.files.3d.printer.guide.smoothieboard.mosfets.png' width='430px'><br/>
 Note a mosfet can not provide power, if it is not provided power via an input Note a mosfet can not provide power, if it is not provided power via an input
 </div> </div>
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 === Configuration === Configuration
  
-||~ Option ||~ Example value ||~ Explanation ||+Option Example value Explanation |
 {{page>spindle-options}} {{page>spindle-options}}